An endoscope with a tool

ABSTRACT

An endoscope having a handle with a handle housing arranged at a proximal end of the endoscope and an insertion tube extending from said handle and terminating in a tip part of a bending section at the distal end of the endoscope, the bending section comprises a distal tubular end segment and a plurality of articulated bending segments, the bending section comprises an intermediate segment between the proximal distal end segment and the plurality of articulated bending segments, wherein the intermediate segment is longer than a bending segment and the distal end segment.

The present invention relates to an endoscope, in particular but notexclusively a disposable camera endoscope, having an operating handlearranged at a proximal end thereof and an insertion tube extending fromsaid handle towards a distal end of the endoscope.

In general an endoscope comprises an operating handle at the proximalend and an insertion tube extending from the handle towards the distalend. The handle is adapted to be held by an operator and inter aliacomprises externally protruding operating members connected to internalcontrol means allowing the operator to control the movement of a bendingsection at the distal end of the insertion tube, while advancing thedistal end of the insertion tube to a desired location e.g. within abody cavity of a person. By means of an attached monitoring device, suchas a monitor with a display screen, the location to which the distal endhas been advanced may be inspected using the endoscope. Often, however,inspection is not all that is desired, e.g. where the inspection is tolocate the site for further actions. One such action could be theremoval of an implanted stent, which necessitates the use of a tool.

In this respect WO2013/071938A1 discloses an endoscope with a built intool in the form of a hook adapted to grip e.g. an urological stent,which can then be removed by retracting the endoscope. The endoscope isadapted for single handed use by an operator using the thumb to controlthe movement of the distal tip of the endoscope, and the index finger tocontrol the reciprocating movement of the tool. The built in tool,however, does not allow other actions than gripping. The tool iscontrolled in a separate channel as compared to the working channel,through which fluid may be extracted or infused, or through which othertools may be inserted. Moreover, the full activation of the toolrequires a reciprocating movement both out and in of the tip part of thebending section of the insertion tube of the endoscope. Given thatstereoscopic vision is not available because only a single camera isused, it may be difficult for an operator to efficiently complete thisreciprocating movement in a correct manner.

It is a further object of the present invention to provide an endoscopeallowing the simultaneous control of the more complex actions of theintegrated tool as well as the control of the bending section at thedistal end of insertion tube of the endoscope using a single hand only.

It is a further object of the present invention to provide an endoscopeallowing the simultaneous control of the more complex actions of theintegrated tool during all operating conditions of the distal end of theinsertion tube. According to a first aspect of the invention this objectis achieved by an endoscope having a handle with a handle housingarranged at a proximal end of the endoscope and an insertion tubeextending from said handle and terminating in a tip part of a bendingsection at the distal end of the endoscope, the bending sectioncomprises a distal end segment and a plurality of articulated bendingsegments, said endoscope further comprising a first operating member atthe handle housing for controlling the bending section, a workingchannel extending within said insertion tube and having a distal end anda proximal end, a motion transfer member extending within said workingchannel and adapted to operate a retractable tool at an exit port of thedistal end of the working channel at the tip part in response to theactivation of a further operating member at the handle housing, thebending section comprises an intermediate segment between the distal endsegment and the plurality of articulated bending segments, wherein theintermediate segment is longer than a bending segment.

The provision of an intermediate segment allows accommodation andprotection of at least a part of the motion transfer member or the toolso that the tool may be released from the exit port and retractedproperly under all operating conditions of both the tool and the distaltop. Hence the endoscope may be operated without impairing operation ofthe tool or the bending radii. This is advantageous for all kinds oftools that may be envisaged to be used in combination with theinvention, i.e. different tool types such as a pair grasping forceps,plyers, a needle, a stylet-cannula unit to carry out biopsies, brushesand scissors etc. Thereby the tool may be protected from being bendduring operating of the bending section, i.e. during bending of thearticulated bending segments in order to control the tip part, or to getstuck because it is protected in a part of the bending section where theworking channel is not bended.

In a practically preferred embodiment the distal end segment is longerthan a bending segment.

In a further practical embodiment which is especially advantageous foruse in combination with a pair of grasping forceps, a distal end of saidmotion transfer member comprises a rigid tube section, which is morerigid than the rest of the motion transfer member. The intermediatesegment ensure that the distal rigid tube section is not positioned inthe articulated bending segments where it would be captured anddifficult to release from the exit port at large bending radii.

In a practical embodiment that allows for improved bending properties ofthe articulated bending segments, the motion transfer member comprises ainner motion transfer member and an outer motion transfer member.

In a further practical embodiment that reduces friction between movableparts of the endoscope, the working channel is formed by a tube thatcomprises at least a first proximal section and a second distal sectionwith a first connecting transition connecting the two sections, thesecond section has a higher degree of flexibility than the firstsection, and said outer motion transfer member comprises at least twosections differing from each other in rigidity and with a secondconnecting transition connecting the two sections, wherein the firstconnecting transition and the second connecting transition are staggeredwith respect to each other along the length of the insertion tube.

In yet another practical embodiment the movement of the first operatingmember is limited by the interior of the handle housing. This keepcontrol of the bending radii and that bending radii are not determinedby the cover of the operating handle, but by a predeterminedconfiguration inside the operating handle.

In a further practical embodiment the handle housing comprises aninterior chassis carrying the first operating member, and the chassis isprovided with stop members limiting movement of the first operatingmember.

The invention will now be described in greater detail based onnon-limiting exemplary embodiment and the drawing on which:

FIG. 1 shows an exploded overview of an endoscope according to thepresent invention and how this exploded view is split in a left-handside part and a right-hand side part for better visibility in FIGS. 1aand 1 b,

FIG. 2 shows a perspective view of the fully assembled endoscope of FIG.1,

FIG. 3 shows a monitoring device for mutual connection with theendoscope of FIG. 1,

FIGS. 4a and FIG. 4b show partial views of the endoscope of FIG. 1 withthe tool operating member in released and depressed state, respectively,

FIG. 5 shows details of the insertion tube of the endoscope,

FIG. 6 shows bending section of the endoscope,

FIG. 7 shows a detail of the bending section,

FIG. 8 shows show an internal chassis of the endoscope,

FIG. 9 shows the chassis of FIG. 8 with a rack and pinion mounted,

FIG. 10 shows the chassis of FIG. 9 partially mounted in the handlehousing partially mounted in the handle housing and with rack and pinionof FIG. 9 attached to a motion transfer means,

FIG. 11 corresponds to FIG. 10 but with the motion transfer meansenclosed in a part of the working channel of the endoscope,

FIG. 12 shows a first perspective view of the pinion of FIG. 9,

FIG. 13 shows a perspective view of the rack of FIG. 12,

FIG. 14 shows a second perspective view of the pinion of FIG. 9,

FIG. 15 shows a first perspective view of the rack and pinion of FIG. 9in mutual engagement,

FIG. 16 shows a second perspective view of the rack and pinion of FIG. 9in mutual engagement,

FIG. 17 shows a plan view of the rack and pinion of FIG. 9 in mutualengagement, and

FIGS. 18a-c show different sectors of motion transfer means comprising afirst motion transfer member and a second motion transfer member.

Turning first to FIG. 2 an assembled endoscope 1 according to thepresent invention is shown. The endoscope 1 has a proximal end with anoperating handle 2 to be held in one hand by an operator. Accordingly,the operating handle is shaped in a manner ergonomically suitable foroperator, in particular but not exclusively for the hand of theoperator, as arms and joints may also play a role in the ergonomics.From the handle 2 an insertion tube 3 extends towards the distal end ofthe endoscope. At the distal end of the endoscope 1 the insertion tube 3ends in a bending section 4 and a tip part 5. The bending section 4 isin mechanical connection with a first operating member 6, digitallyoperable by the operator, e.g. by the thumb, thereby allowing theoperator to bend the tip part 5 in a desired direction when advancingthe insertion tube 3 towards a desired location, e.g. through a bodycavity of a patient. In addition to the first operating member 6 theendoscope 1 comprises a tool operating member 22 adapted to operate atool 55 at the tip part 5 of the endoscope 1. The tool operating member22 is preferably in the form of a trigger or push-button so accommodatedin the housing that it may be operated by the same hand as used foroperating first operating member 6. In the configuration shown the firstoperating member 6 is adapted to be operated by the thumb of theoperator whereas the push-button is adapted to be depressedindependently thereof by the index finger of the very same hand of theoperator. This allows singled handed use of the endoscope. As can beseen the push-button is has been partially depressed allowing the tool55 to be advanced forwardly from the distal end of the tip 5 of theendoscope 1. This partially depressed position which will be describedin greater detail later is an intermediate position between the fullyreleased position shown in FIG. 4a , towards which the push-button ispreferably spring biased, and the fully depressed position shown in FIG.4b , which will also be described later.

As can also be seen in FIG. 2, the endoscope 1 comprises a flexibleconnection cable 7 with a connector 8 allowing the endoscope 1 to beconnected to a monitoring device such as a monitor 92 shown in FIG. 3forming part of an endoscope 1 and monitor 92 system.

Turning now to FIGS. 1, 1 a and 1 b an exploded view of the endoscope 1is shown. As mentioned, the endoscope 1 has an operating handle 2 at theproximal end thereof i.e. at the left-hand side of FIG. 1 a. Theoperating handle 2 is assembled from and comprises a number of handleparts to be described later. From the operating handle 1, the insertiontube 3 comprising a number of insertion tube parts to be described laterextends towards the distal end of the endoscope, i.e. towards theright-hand side of FIG. 1 b. The first operating member is is connectedto a control lever 37 which is mounted in the handle 1 by means oftrunnions 26 positioned in pivotal bearing 38 (cf. FIG. 8). The controllever 37 allows manoeuvring of the bending section 4 via a Bowden cablearrangement 27 comprising pull-wires 31 and outer guide tubes 60. Thecontrol lever 37 is attached to the first operating member 6, and atleast the first operating member 6 extends to the outside of theendoscope handle 2 through a slit in the shell part 10 to be accessibleby a thumb of the an operator. As can be seen in FIG. 1a the controllever 37 may be provided with a protruding tap 35 for limiting movementof the control lever 37 and thereby the bending radius of the bendingsection 4. This is achieved by providing the interior of the operatinghandle 2 with one or more stop members 36 a, 36 b that limit movement ofthe control lever 37 by only allowing movement of the tap 35 between thetwo stop members.

The operating handle 2 comprises at least two shell parts 9, 10 formingthe outer housing walls of the handle housing of the operating handle 2.The two shell parts 9, 10 form the outer housing walls and are shaped toprovide an ergonomically suitable operating handle for an operator,gripping it with one hand. In addition to the two shell parts 9, 10 atransition part 11 forming the transition from the operating handle tothe insertion tube 3, may be provided. This transition part may alsoform part of the handle housing. However, the two shell parts 9, 10constitute the major part of the housing in the embodiment shown. Theshell parts 9, 10 and almost all other parts are mounted on a chassis12.

Turning now to FIG. 5 details of the distal end of the insertion tube 3with the articulated bending section 4 is shown. Some parts, such as anexternal sheath 80 normally covering the bending section 4, have beenremoved for clarity. The bending section comprises a number of segments61, 62, 65, 66. More specifically a distal end segment 61, a proximalend segment 65 (not fully visible in FIG. 5), a plurality of articulatedbending segments 62 and an intermediate segment 66. In the illustratedembodiment, the number of bending segments 62 are is six, but theskilled person will understand that the precise number is lessimportant. The distal end segment 61 is tubular shaped with an interiorend wall towards the intermediate segment 66. The interior end wall isprovided with through holes for fastening the pull wires 31. I.e. distalend segment 61 has a generally circular cross section with one passagefrom the end wall to the most distal part. The end wall is adapted withopenings to allow passage of electrical supply wires and pull-wires. Thetubular shape allows the distal end segment 61 to least partiallyaccommodate a camera module 64 comprising a camera, light emittingdiodes and electronic circuits as well as it accommodated a portion of atube 72 forming a part of a working channel. The working channel extendsinside the insertion tube 3 all the way from the distal tip part 5 tothe operating handle 13 and is formed by tube 72 and tube 73, which areconnected by a connecting tube member 74. The working channel may via asuction port 76 on the handle be connected to a standard externalsuction, e.g. wall suction present in hospital environment by means ofan attached tube.

One embodiment of the bending section 4 is shown in FIG. 6 without anyattached parts. It can be seen that there is one distal end segment 61,one proximal end segment 65, an intermediate segment 66 and sixarticulated bending segments 62. The bending segments 62 areinterconnected by means of flexible hinge members 63 formed by cut-outs25 between the hinge sections 62. As can be seen from FIGS. 5 and 6 theintermediate segment 66 is longer than the bending segments 62.Preferably, the intermediate segment 66 is also longer that the distalend segment 61. Hence in the embodiment of FIGS. 5 and 6 theintermediate segment 66 has a length l₁, which is longer than a lengthl₃ of the distal end segment 61 and a length l₂ of a bending segment 62,where the distal end segment 61 has a length l₃, which is longer that alength l₂ of a bending segment. In a preferred embodiment the length l₁of the intermediate segment is about 1.5-3 times the length 1 ₃ of thedistal end segment and is 4-5 times the length 1 ₂ of a bending segment.

The bending segments 62 generally have the same cross-section, whichgenerally correspond to the end view of FIG. 7. That is to say agenerally circular cross-section with four passages 67, 68, 69. Thefirst passage 67 is circular and adapted to engage and support the outerwall of the tube 72 forming a portion of the working channel. This firstpassage is relatively large, and the centre 70 of the cross-section ofthe bending segments actually lies within the first passage 67. Thesecond passage 68 is adapted to accommodate electrical supply wires forthe camera module 64. The camera and the light emitting diodes aremounted on a small circuit board to which the supply and signal wiresare connected. The last two passages are pull wire passages 69 forguiding pull wires 31 of a Bowden cable arrangement 27, where the pullwires are guided in outer guide tubes 60. The pull wire passages 69 arearranged symmetrically opposite each other on either side of the planein which the hinge members 63 extend. Preferably, the intermediatesegment 66 have the same cross-section as shown in FIG. 7, i.e. the sameas the bending segments 62.

The ends of the pull-wires are secured in the distal end segment as wellas connected to the control lever 6 in the operating handle 2. Thus bymanipulating the control lever 6 the pull wire may be tensioned on oneside of the plane of the hinge members 63 and slacked on the other, thusallowing the articulated bending section 4 to bend in a desireddirection. The distal end segment preferably also has a number ofcut-outs, preferably through holes. These help securing the cameramodule and the end of the tube 9 etc. when these are moulded-in by meansof plastic material, e.g. in a process similar to the one described inWO-A-2010/066790 incorporated herein by reference. As seen in FIGS. 5and 6 the bending section 4 is provided with a recess 25 between thedistal end segment 61 and the intermediate segment 66. This most distalrecess 25 is provided to facilitate assembly and fastening of thepull-wires to the distal end segment 61 in a preferred embodiment,wherein the tip part 5 is moulded as described above and where distalrecess 25 is at least partly filled with moulding material for moundingthe tip part 5 so that the distal end segment 61 and the intermediatesegment 66 are fixed to each other in a non-articulated manner.Evidently, the pull-wires may be fastened to the proximal portion of theintermediate segment 66. Alternatively, the pull-wires may be affixed tovia through holes at a proximal part of the intermediate segment wherean outer surface of the intermediate segment is provided with aperturesfor allowing guidance of the pull-wires to and from the through holesduring assembly of the pull-wires.

As best seen in FIG. 8, the chassis 12 preferably shell shaped, i.e. thechassis 12 comprises an essentially shell shaped structure with a shellwall having an inner surface 16 and an outer surface 17 linked by anedge 18, said essentially shell shaped structure defining an interiorcompartment 19 delimited by said inner surface 16 and the edge 18 of theshell wall, the edge thus defining main opening 20 of said interiorcompartment 19. It will be understood that the chassis 12 can bedesigned mainly based on technical requirements, in such as kinematicchains of movable parts to be described further below, and thus beoptimized for those technical requirements without having to inheritconstraints from the ergonomic requirements of the handle 2, i.e. theshape of the two shell parts 9, 10.

As mentioned above, the chassis 12 is adapted to for the mounting ofalmost all parts of the endoscope 1. In particular, the chassis 12 isadapted for holding movable parts forming of kinematic chain from thepush-button forming the tool operating member to the motion transfermeans transferring the movement of the tool operating member 22 to thetool 55.

One such adaptation is a pair apertures 41 in the form of essentiallycylindrical through holes can be seen in FIG. 1 a. The apertures 41serve as bearings of trunnions 42 carrying rotary member such as apinion 44, best visible in FIG. 12. As can be seen from FIGS. 15 to 17,the pinion 44 is adapted to be in engagement with a curved rack 45. Thecurved rack 45 is shown separately in FIG. 13. The curved rack 45 has afirst free end 46 and a second end with trunnions 47 held loosely insuitable receptacles inside the push button forming the tool operatingmember 22. The rack 45 as such is loosely held in a guideway comprisinga first side 85, a second side 86 and a curved bottom 87 adapted to keepthe rack 45 in engagement with the pinion 44. The first side 85 and thesecond side 86 as well as the curved bottom 87 are preferably formedintegrally with the remainder of the chassis 12, e.g. in an injectionmoulding process. The first side is preferably constituted by a planesurface of a thickened part of the wall, i.e. a raised part of the innersurface 16 of the chassis 12.

Rotation of the pinion 44 may be effected by an operator moving thepush-button forming the tool operating member 22, e.g. depressing itusing an index finger, upon which the push-button forming the tooloperating member 22 transfer motion to the curved rack 45, in turnrotating the pinion 44.

On the pinion 44, two levers 48 and 49 are provided. These levers 48 and49 are in rigid connection with the pinion 44. The levers 48 and 49 havedifferent lengths so as to influence a first motion transfer member 53and a second transfer member 54 of the motion transfer means indifferent ways in order to effect a compound movement of the tool 55. Aswill be described later this compound movement comprises both a linearmovement of the tool 55 and a task movement of the tool 55.

As can best be seen in FIG. 1 a, the first motion transfer member 53 isarranged co-axially within the second motion transfer member 54. Thefirst motion transfer member 53 and the second motion transfer member54, in turn, are arranged within in tubular members 71, 72, 73, 74,which form part of the working channel of the endoscope, together withan e.g. T- or Y-shaped bifurcated section 75 providing the entry port tothe working channel.

As can best be seen from FIGS. 18a-18c the first and second motiontransfer members 53, 54 each comprise different sectors with differentrigidities or bending properties, matching the requirements of theinsertion tube 3, and the working channel, which both also has differentbending properties along the length thereof. The first motion transfermember 53 preferably comprises a rigid rod piece at the proximal end anda rod or tubular piece at the tool 55. Between the two, the first motiontransfer means may comprise a flexible wire.

The first motion transfer member 53 is terminated in an end sealingmeans 51. Apart from sealing the proximal end of the working channel,the end sealing means also serves as part a first kinematic chain bybeing pivotally connected to the first lever 48.

The first kinematic chain is as follows: Depressing the tool operatingmember 22 will move the rack 45 in a curvilinear movement via thetrunnions 47. The rack 45, which has teeth in permanent engagement withthe pinion 44, will rotate the pinion 44 and the first lever 48 rigidlyconnected thereto. The rotating first lever will consequently push theproximal end of the first motion transfer member 53, causing the tool 55arranged at distal end of the first motion transfer member 31 to bemoved out of the working channel beyond the distal end of the insertiontube 3 of the endoscope 1. Being spring biased, by e.g. a pair coilsprings 83 accommodated in the chassis 12, a release of the tooloperating member 22 will automatically return the tool operating member22 to the position of FIG. 4 a.

The second motion transfer member 54 forms a sheath for the first motiontransfer member and preferably comprises a coil spring part 54 a woundfrom wire with a rectangular cross section towards the proximal end, anda coil spring part 54 b wound from wire with a circular or round crosssection towards the distal end. Preferably, the outer motion transfermember comprises at least two sections 54 a, 54 b differing from eachother in rigidity and with a second connecting transition 56 connectingthe two sections 54 a, 54 b. At the distal end, the secand motiontransfer member is terminated in a rigid tubular member 95.

The second motion transfer member 54 is terminated in a first tubularend member 52. The rigid part of the first motion transfer member 53passes coaxially trough the first tubular end member 52 and into theremainder of the second motion transfer member 54. The passage throughthe first tubular end member 52 as well as through the remainder of thesecond motion transfer member 54 is adapted to allow mutual lengthwiserelative motion, i.e. mutually reciprocating movement.

Not unlike the sealing end member 51, the first tubular end member 52serves as part of a second kinematic chain adapted to provide adifferent motion pattern of the second motion transfer member 54 ascompared to the first motion transfer member 53 in response to the verysame depression, i.e. one and the same as the one described above. Thisis achieved by the second lever 49 which is also rigidly attached to thepinion 44 but has a different length than the first lever 48. At the endof the second lever 49 a first arm 50 is provided in articulatedconnection with said second lever 49. The second end of the first arm 50is in articulated connection with a clamping means 79 adapted to clampthe tubular end means 52 with a part 71 of the working channel wallinterposed. The interposed part 71 is preferably a flexible hose part.Preferably, the flexible hose part is made from the very same tubularmaterial as is used to form the outer sheath 80 of the insertion tube 3at the distal end around the bending portion 5. To ensure good gripbetween the interposed part of the working channel wall 71 and the firsttubular end member 52 the first tubular end member may compriseconcentric ribs 98 or corrugations, or similar means. The articulationsof the first arm 50 are preferably provided as integrally moulded foilhinges 93, as best seen in FIG. 15.

Accordingly, the second kinematic chain is as follows: Depressing thetool operating member 22 will move the rack 45 in a curvilinear movementvia the tool trunnions 47. The rack 45, which has teeth in permanentengagement with the pinion 44, will rotate the pinion 44 and the secondlever 49 rigidly connected thereto, so as to change their relativeposition while remaining in the engagement. The rotating second lever 49will consequently push the proximal end of the first arm 50, therebymoving clamping means 79 at distal end of the first arm 50, articulatingthe first arm 50 as necessary in the foil hinges 93. The clamping means79 moves the clamped part of the working channel wall part 71. Beingclamped, the clamped part of the working channel wall 71 moves the firsttubular end member of the second motion transfer member 54 towards thedistal end of the working channel, consequently causing the distal endof the second motion transfer member 54 to be moved out of the workingchannel beyond the distal end of the insertion tube 3 of the endoscope1. The distal end of the second motion transfer member 54 is preferablyterminated in a second tubular end member 95. Being spring biased, bye.g. a pair coil springs 83 accommodated in the chassis 12, a release ofthe tool operating member 22 will automatically return the tooloperating member 22 to the position of FIG. 4 a.

Providing these two different kinematic chains allows the tool 55 toperform a compound movement comprising both a linear movement and a taskmovement, during one continuous depression of the tool operating member22. In the linear movement, the tool 55 is advanced to a position infront of the distal end of the insertion tube 3 of endoscope 1 where itis visible from the camera built into the tip part 4 of the endoscope 1,and hence visible by the operator on the monitor 92 attached to theendoscope via cable 7 and connector. This may be performed by onlypartially depressing the tool operating member 22, e.g. to the positionshown in FIG. 2, where with a suitable layout of the first kinematicchain will not advance any further but remain stationary or at leastalmost stationary with respect to the distal end of the insertion tube 3of the endoscope even if the tool operating member is depressed further.Having located the correct position for operating the tool 55, e.g. bylaterally moving the tip 4 of the bending section 5 at the distal end ofthe insertion tube 3 of the endoscope 1 using the first operating member6 simultaneously with the tool operating member, the task movement canbe performed.

In the preferred embodiment the tool 55 at the distal end of the firstmotion transfer member 53 comprises a self expanding configuration, suchas a pair of spring tweezers, forceps, a spring loop, or the like whichas long as it is accommodated in the tubular member 95 is compressed, asshown in FIG. 18b . Accordingly, it will auto-expand if it is advancedout the second tubular member 95, to the configuration shown in FIG. 2.Now, due to the second kinematic chain operating independently of thefirst kinematic chain, the second motion transfer member is heldstationary is in the working channel during the first part of thedepression of the tool operating means 22 to the intermediate position.Then, still due to the independent operation of the first and secondkinematic chains, continuing the continuous movement by furtherdepressing of the tool operating member 22 will cause the second motiontransfer member to also start moving thereby advancing the secondtubular end member 95. Consequently, the second tubular end member 95slides over the tool 55 again, because as mentioned above the firstkinematic chain is laid out to keep the tool 55 stationary in the fieldof vision of the camera at a distance from the tip part 4 of theinsertion tube 3 of the endoscope 1. This will the effect the taskmovement of closing the tool 55 because the configuration as show inFIG. 18b is now restored, but this time at the position at the locationoutside the working channel set at the intermediate depression of thetool operating member 22. Keeping this position is of outmost benefitfor the operator, who having only one camera eye does not perspectivevision and therefore as difficulties in judging distances. Thus, havingfound the position where a stent a other object is to be gripped, e.g.by touching them with the tool, the operator can do so without furtheradvancing or retracting of the entire endoscope 1.

Having gripped object, such as a stent, with the tool 55 in this way theobject may then be removed from the body by retracting the entireendoscope 1 from the cavity whilst holding the tool operating member 22depressed.

For the sake of clarity it should be noted that the term continuousmovement is merely to be understood as a movement of the tool operatingmember from released state to a depressed state. It does not imply thatthe movement cannot be paused by the operator during the continuousmovement. It does also not imply that the movement cannot be partiallyreversed by the operator releasing the tool operating member 22, in thesearch for the gripping location. In fact a latch means may be includedto partially intermit the procedure without the tool changing itsposition. This could be a simple click mechanism as is well known in theart, latching when the tool operating member 22 is depressed fully, andreleasing upon repeated depression og the tool operating member 22. Asmentioned above, and as can be seen from FIGS. 13 and 15-17 the rack 45has a curvature. This curvature preferably matches the curvature of thecurved bottom 87 of the guideway, so that the teeth of the rack 45 arekept in engagement with the matching teeth of the pinion 44. Thiscurvature saves space helping to fit the rack 45 and pinion 44 mechanismwithin the chassis 12 and the handle housing 2. The skilled person willunderstand that the forces and torques of the kinematic chain may bealso be influenced by suitable choice of curvature and length of therack 45 and diameter of the pinion 44 provided it is generally circular.The pinion 44 with a generally oval shape or other curvature is alsoenvisaged. The skilled person will also understand that the twokinematic chains, and in particular their mutual differences could beinfluenced by suitable choice of the length of the levers 48 and 49,their angular spacing on the pinion 44, and the length and articulationsof the arm 50, as well as by the provision of further arms. This mayallow specific adaptation of the kinematic chains to the specificrequirements of different tools 55.

As will be understood from the above the first and second motiontransfer members are located within the working channel of the endoscope1, comprising tubular members 71, 72, 73, 74 forming a generally tubularworking channel wall and an e.g. T- or Y-shaped bifurcated section 75providing the entry port to the working channel.

Starting from the distal end of the endoscope 1, a first tubular member72 adapted to comply with the bending requirements of the bendingsection 5 of the endoscope 1 is provided. The first tubular member 72passes through the bending section and thus provides an exit port 96 ofthe working channel at the tip 4 thereof. Via a short joint tube 74, asecond tubular member 73 is joined at one end with the first tubularmember 72 and provides a longer intermediate section of the workingchannel. Hence the working channel is formed by a tube that comprises atleast a first proximal section 73 and a second distal section 72 with afirst connecting transition 74 connecting the two sections.

From the perspective view in FIG. 1b it is realized that it is preferredthat the connecting transition member 74 of the working channel and theconnecting transition member 56 of the second motion transfer member 54are staggered with respect to each other along the length of theinsertion tube 3. Hence when the second motion transfer member 54 ismoved back and forth along the inside of the working channel the twotransitions are staggered along the length of the insertion tube in allconditions of use.

The second tubular member 73 is generally more rigid than the firsttubular member 72. The second tubular member 73 is however still quiteflexible. More specifically, the second tubular member 73 and a secondouter tube section 81 surrounding it are so flexible that they allow aloose knot to be tied on the insertion tube 3. The alternative is arigid or semi-rigid endoscope where the insertion portion is rigid, onlyslightly bendable or hinged, and which does not allow a knot to be tiedon the insertion tube. It is preferred to make the first tubular member71 of a first polyurethane elastomer and to make the first tubularmember 72 of another polyurethane elastomer. Both polyturethaneelastomers could be Pellethane®, which is available in differentvariants. The second tube member 73 may also comprise polyurethane. Atthe other end of the second tubular member 73, the second tubular member73 is joined to a first branch of a preferably T-shaped bifurcatedsection 75. The bifurcated section has s second branch which providesthe entry port to the working channel together with a connector 76 orlead-in mounted on the chassis 12. In the preferred embodiment shown thebifurcated section is 75 T-shaped. That is to say perpendicular that thesecond branch is perpendicular to the first branch. Evidently the secondbranch could also be arranged a different angle, so as to provide moreof a Y-shape. The connector 76 allows a suction means to be attached forextracting fluid from a body cavity via the working channel.Alternatively a fluid source may be attached to the connector 76,allowing e.g. irrigation or aspiration of the body cavity via theworking channel. The third branch of the bifurcated section 75 ispreferably aligned with the first branch so as to provide anunobstructed straight passage through the bifurcated section 75 for thefirst and second motion transfer members 53, 54. To the third branch ofthe bifurcated section a firs end of a third tubular member is attached,which at least in the released position of the operating member 22 isaligned with the first and third branch of the bifurcated section 75 andthe second tubular member 73, when the latter is in a relaxed position,i.e. not influenced by external forces from body cavity walls or helike. The second end of the third tubular member 71 forms the proximalend of the working channel, and is terminated in an end sealing means51. As described above end sealing means, not only seals the proximalend of the working channel, but also serves as part a first kinematicchain by being pivotally connected to the first lever 48. The thirdtubular member 71 is preferably in the form of a hose of a highlyflexible material, as compared to the remainder of the tubular membersforming the working channel. The hose could be provided withcorrugations or the like to from a bellows. Making the third tubularmember of a highly flexible material serves two purposes.

The first purpose is that it allows the length of the working channel toadapt to the movement of the members of the first kinematic chain inparticular the first lever 48, the first motion transfer member 53 andthe interposed end sealing member 51. The flexible material allows theworking channel to deform in order to adapt in length to accommodate themovement of the first motion transfer member. However, by being flexiblethe material also allows working channel to deform in order to complywith the swinging movement of the end sealing member caused by the firstlever 48 moving the end sealing member 51 out of alignment with thefirst and third branches of the bifurcated member 75 and second tubularmember 73. By being able to comply with these movements, the thirdtubular member 71 allows transfer of movement using parts of the workingcannel itself, in turn, allowing transfer of movement from the operatingmeans 22 to the tool 55 without breaching the integrity of workingchannel wall. Undesired ingress of pollutants is thus avoided.

The second purpose is similar to the first purpose, because by beingflexible the material also allows working channel to deform in order tocomply with the movement of the members of the second kinematic chain,in particular the movement of the first tubular end member 52 caused bythe second lever 49 in conjunction with the arm first 50. As mentionedabove this movement is transferred via the working channel wall, becausethe third tubular member 72 is clamped between the first tubular endmember 52 and clamping member 79. By being able to comply with thesemovements, the third tubular member 71 allows transfer of movement usingparts of the working cannel itself, in turn, allowing transfer ofmovement from the operating means 22 to the tool 55 without breachingthe integrity of working channel wall. Undesired ingress of pollutantsis thus avoided.

Clamping the third tubular member 72 in this way between the clampingmember 79 and first tubular end member 52, provide minor problems whichthe present invention also overcomes. One problem is to ensure good gripso that the relative position between the clamping member 79 and thefirst tubular end member 52 does not change due to the forces in thekinematic chain when the tool 55 is operated. The first tubular endmember 52 the first tubular end member may comprise concentric ribs 98or corrugations, or similar means. A second problem is with thisconfiguration of the working channel with a sealed appendix at theproximal end, the output port at the distal end, and entry port locatedbetween them, it becomes difficult to sterilize the interior of theappendix, in particular the proximal end thereof between the end sealingmeans 51 and the first tubular end member 52, because the access ofsterilizing fluid, such as Ethylene Oxide, may be blocked by the firsttubular end member 52. Sterilisation with Ethylene Oxide (ETOsterilization) is preferred for sterilisation, because the endoscope 1according to the invention is preferably a disposable endoscope madefrom low cost materials, which may not necessarily withstand othersterilization processes such as the high temperature and pressure of anautoclave sterilisation.

Accordingly, as can be seen in FIG. 15a an elongate groove along thefirst tubular end member 52 and across the concentric ribs 98 isprovided. In assembly this groove is made to register with gap in theclamping means 79, so as to allow an open fluid passage along the firsttubular end member 52. Preferably, the inner diameter of the thirdtubular member 71 is selected to be larger than the largest outerdiameter of the first tubular end member 52 so as to form a pouch in thefirst tubular member 71 also registering with the groove 99.

A third problem is that using the working channel wall as a part of thekinematic chains, and therefore in the second kinematic chain grippingand the third tubular member 71 somewhere between the sealing end member51 and the bifurcated section 75, may cause inadvertent overstretchingof the flexible material of the third tubular member, leading, in turn,to an undesired rupture of the working channel wall. To overcome this, astrike plate 59 is provided in the chassis 12. When the clamping member79 is moved under the by depression of the operating member 22 by theoperator, the clamping member will strike the underside (as understoodwith reference to FIG. 1) of the strike plate 59, and will be limited infurther motion. Thus even if the operator presses inappropriately hardon the operating member 22, the clamping means will not tear the thirdtubular member 71 and breach the integrity of the working channel wall.Preferably, the strike plate serves the dual purpose of alsoaccommodating electronics of the endoscope 1 such as a printed circuitboard 62.

The present invention thus provides an endoscope with a working channel,used not only for accommodating parts of the control mechanism of a toolbut also forming itself a part of the control mechanism. The skilledperson will understand that the arrangements described above, and inparticular the kinematic chains are only exemplary embodiments, and thatthe endoscope according to the present invention may be devised in manydifferent variants without departing from the scope of the invention asexpressed in the claims.

What is claimed is: 1-7. (canceled)
 8. An endoscope comprising: a handlewith a handle housing arranged at a proximal end of the endoscope; aninsertion tube extending from the handle with a bending section at adistal end and terminating in a tip part of the bending section, thebending section comprising a distal end segment, an intermediatesegment, and a plurality of articulated bending segments, wherein theintermediate segment is connected to and between the distal end segmentand the plurality of articulated bending segments, and wherein theintermediate segment is longer than a bending segment from the pluralityof articulated bending segments; a first operating member at the handlehousing for controlling the bending section; a working channel extendingwithin the insertion tube and having a distal end and a proximal end; atool operating member at the handle housing; a retractable tool; amotion transfer member connected to and between the retractable tool andthe tool operating member, the motion transfer member extending withinthe working channel to operate the retractable tool at an exit port ofthe distal end of the working channel at the tip part in response to theactivation of the tool operating member.
 9. The endoscope of claim 8,wherein the distal end segment is longer than the bending segment fromthe plurality of articulated bending segments.
 10. The endoscope ofclaim 8, wherein a distal end of the motion transfer member comprises arigid tube section, which is more rigid than the rest of the motiontransfer member.
 11. The endoscope of claim 8, wherein the motiontransfer member comprises an inner motion transfer member and an outermotion transfer member.
 12. The endoscope of claim 11, wherein theworking channel is formed by a tube that comprises at least a firstproximal section and a second distal section with a first connectingtransition connecting the two sections, wherein the second section has ahigher degree of flexibility than the first section, wherein the outermotion transfer member comprises at least two sections differing fromeach other in rigidity and with a second connecting transitionconnecting the two sections, and wherein the first connecting transitionand the second connecting transition are staggered with respect to eachother along the length of the insertion tube.
 13. The endoscope of claim8, wherein movement of the first operating member is limited by theinterior of the handle housing.
 14. The endoscope of claim 13, whereinthe handle housing comprises an interior chassis carrying the firstoperating member, and wherein the chassis comprises stop memberslimiting movement of the first operating member.
 15. An endoscopecomprising: a handle including a handle housing having an interior, abending portion operator extending partially through the handle housing,and a tool operator extending partially through the handle housing; aninsertion tube extending from the handle and including a bending sectionconnected to the bending portion operator and terminating in a tip parthaving an exit port, the insertion tube including a working channelextending within the insertion tube and having a proximal end and adistal end; and a motion transfer member extending at least partlywithin the working channel and comprising a rigid tube section and aportion less rigid than the rigid tube section, the motion transfermember and the tool operator configured to connect to a retractable toolpositioned at the distal end of the working channel, wherein in areleased position the tool operator is configured to at least partiallyposition the retractable tool in the bending section, wherein in anintermediate position the tool operator is configured to position theretractable tool in an extended position wherein the retractable toolextends past the exit port, and wherein in a depressed position the tooloperator is configured to position the retractable tool in the extendedposition and to extend the rigid tube section to at least partiallyoverlap the retractable tool thereby actuating the retractable tool, andwherein the intermediate position is intermediate the extended positionand the depressed position.
 16. The endoscope of claim 15, wherein therigid tube section is more rigid than the rest of the motion transfermember.
 17. The endoscope of claim 15, wherein the motion transfermember comprises an inner motion transfer member and an outer motiontransfer member.
 18. The endoscope of claim 15, wherein the interior ofthe handle housing is configured to limit movement of the bendingportion operator.
 19. The endoscope of claim 15, wherein the handlehousing comprises an interior chassis configured to carry the bendingportion operator, and wherein the chassis comprises stop membersconfigured to limit movement of the bending portion operator.
 20. Anendoscope comprising: a handle including a handle housing having aninterior, a bending portion operator extending partially through thehandle housing, and a tool operator extending partially through thehandle housing; an insertion tube extending from the handle andincluding a bending section connected to the bending portion operatorand terminating in a tip part having an exit port, the insertion tubeincluding a working channel extending within the insertion tube andhaving a proximal end and a distal end; a motion transfer memberextending at least partly within the working channel and comprising arigid tube section and a portion less rigid than the rigid tube section;and a retractable tool positioned at the distal end of the workingchannel and connected by the motion transfer member to the tooloperator, wherein, in a released position of the tool operator, theretractable tool is at least partially positioned in the bendingsection, in an intermediate position of the tool operator, theretractable tool extends past the exit port to an extended position, andin a depressed position of the tool operator, the retractable tool is inthe extended position and the rigid tube section is extended and atleast partially overlaps the retractable tool thereby actuating theretractable tool, wherein the intermediate position is intermediate theextended position and the depressed position.
 21. The endoscope of claim20, wherein the rigid tube section is more rigid than the rest of themotion transfer member.
 22. The endoscope of claim 20, wherein themotion transfer member comprises an inner motion transfer member and anouter motion transfer member.
 23. The endoscope of claim 20, wherein theinterior of the handle housing is configured to limit movement of thebending portion operator.
 24. The endoscope of claim 20, wherein thehandle housing comprises an interior chassis configured to carry thebending portion operator, and wherein the chassis comprises stop membersconfigured to limit movement of the bending portion operator.